Shade-tolerance Of 3 Ornamental Ferns

Changes of leaf characters (length, width and area ), physiological characters (chlorophyll contents and photosynthetic characters) and ornamental feature of 3 ornamental ferns including Nephrolepis auriculata, Davallia mariesii and Beauty Fern were searched with four different sun-shading treatments (CK 77%,T1 50%,T2 28%,T3 5%) in this paper. The results show that:(1) Shading treatments have an obvious effect on the leaf characters of three ornamental ferns. With the increasing of sun-shading, the data of length,width and area of leaves has had the different changes, compares CK to be smallest. The relative growth of length,width and area of Nephrolepis auriculata and Beauty fern increased with the increasing of sun-shading. Davallia mariesii is a bit difference. With the increasing of sun-shading, its tendencies displayed to be up first and then down, which reached the maximum at 28% entire illumination condition. At 28～5% entire illumination, the length, width and area got reduced.Using gradient analysis on the length, width and shading levels, the result shows that the characters above achieved the remarkable level (P<0.05). In the four treatments, the leaf relative growth of T2 and T3 level is obviously high which has reached the extremely remarkable level (P<0.01).(2) The influence of shading treatments to fresh-weight per area of ornamental ferns. Beauty fern's fresh-weight per area increases along with the increasing of sun-shading. The T1, T2 and T3 level compared to CK increased 2.47%, 9.28% and 14.53%. The fresh-weight per area of Nephrolepis auriculata and Davallia mariesii displayed to be up first and then down with the increasing of sun-shading, and the turn from large to small is: T2>T3>T1>CK.(3) Three kind of ornamental fern's chlorophyll content increased with the increasing of sun-shading. The chlorophyll (T) content from high to low in turn is Nephrolepis auriculata > Davallia mariesii > Beauty fern. The value of chlorophyll a/b turned in a consistent performance with the changing of luminous intensity, which reached the largest at 77% luminous intensity and the smallest at 5% luminous intensity. In the all shading treatments, Beauty fern's chlorophyll a/b are bigger than Nephrolepis auriculata and Nephrolepis auriculata's bigger than Davallia mariesii. Carried on the relevant analysis separately to the three kind of ornamental fern's chlorophyll content (T) and chlorophyll a/b, the result indicates that the relative factor of Nephrolepis auriculata 's chlorophyll content (T) and a/b is 0.8272, reached the remarkable level, while Davallia mariesii and beauty fern reached the extremely remarkable level, the relative factors are 0.8582and 0.9938.(4) There was some efficiency of net photosynthetic rate to shading treatments. The curves diurnal variation of net photosynthetic rate of Nephrolepis auriculata and Davallia mariesii with different environments and which of Beauty fern with CK, T1 and T2 treatments presented two peaks, while there was only one peak to Beauty fern with T3 treatments.(5) The ornamental fern's utilization ratio of light energy increased with the increasing sun-shading. In certain shading scope, from the utilization ratio of light energy, the order of the three ornamental fern's adaptation is: Nephrolepis auriculata>Beauty fern> Davallia mariesii. In which the three got the largest utilization ratio of light energy at 5% luminous intensity.(6) The curves diurnal variation of Gs and Tr of three ornamental fern were similar to the net photosynthetic rate, but not synchronization. The relevant analysis indicated that the Pn and Gs, Tr had the remarkable correlation.(7) The curves diurnal variation of average Ci was opposite to the average net photosynthetic rate. With the increasing of the sun-shading, the average net photosynthetic rate decreased, while the Ci increased gradually.(8) Ornamental feature: Shading for 3 months, the fern with CK treatment appeared different withered phenomenon for high temperature and intensely illumination. The wizened leaves of Nephrolepis auriculata and Davallia mariesii reached 50%, and the sense effect was poor, therefore the score was low. The Davallia mariesii with 28% and 5% luminous intensity leaves verdant and gloss, no withered and yellow phenomenon, elegant and plentiful, had the best ornamental effect, so got a high score. While Nephrolepis auriculata appeared withered and yellow phenomenon in varying degree and got a low score. The leaves of Beauty fern are olivine, organ sense is poor. Three ornamental fern are adapted to live with 28% and 5% luminous intensity and can maintain ornamental character better.Ornamental effect has been changed for shading 6 months. The ornamental effect of the CK treatment got different enhancement, the scorch leaves substituted by soft leaves. For a long time in the low illumination environment, the browse of three ornamental ferns in 28% (T2) and 5% (T3) luminous intensity turned yellow, which affected the organ sense.(9) The shade-tolerance intensity sequence of three ornamental ferns showed some different index value, while the shade-tolerance intensity of Nephrolepis auriculata was obviously greatest, and then was Davallia mariesii, and beauty fern was last.